In some instances bone fusion, or arthrodesis, of anatomy including multiple bone structures may be desirable, such as arthrodesis of the lower extremity bones of the ankle or foot. Foot or ankle arthrodesis is an established surgical technique to join or fuse adjacent bones in the foot or ankle by rigidly positioning them at their articular surfaces. By maintaining this placement, sometimes in the presence of a bone graft, bone cell growth or other anatomical growth may be stimulated which may cause the bones to fuse together. Once the bones are fixed to one another, all motion that existed at the corresponding joint surfaces of the bones ceases, stability is achieved and any pain caused by the irritation of corresponding nerves is significantly reduced or eliminated. For example, in certain patients with post-traumatic arthritis, rheumatoid arthritis, osteoarthritis, instability, complex or localized fractures or other injury, disease or destructive or painful conditions involving the bones of the foot or ankle, fusion of particular bones of the foot or ankle can alleviate resulting pain, discomfort and instability. Unfortunately, effective fusion of the foot or ankle which balances pain relief, joint stability and retention of some effective movement of the foot or ankle is rarely achieved, no less consistently achieved.
Several surgical approaches have been developed to maximize alleviation of foot or ankle pain and/or instability by arthrodesis. For example, total foot or ankle arthrodesis is very effective in relieving pain, but almost all foot or ankle motion is lost. Since the articulation afforded by the foot or ankle is important for mobility, strength and dexterity, such as during walking, running or the like, total foot or ankle arthrodesis is often thought of as a last resort. As another example, limited or partial foot or ankle arthrodesis is often desired in an effort to preserve motion of the foot or ankle to the greatest degree possible. Partial foot or ankle arthrodesis is fusion of a selected group of foot or ankle bones. Variations of the procedure, such as talus-tibia-fibia fusion (hereinafter “ankle fusion”), fibula-tibia fusion, calcaneus-cuboid fusion, talus-navicular fusion, navicular-cuneiform fusion, navicular-talus-cuboid-calcaneus fusion (hereinafter “triple arthrodesis”), cuneiform-metatarsal, tarsal-metatarsal fusion, metatarsal-phalanx fusion (hereinafter “MTP fusion”), and interphalangeal fusions, attempt to alleviate pain by fusing particular articulations determined or suspected of originating pain and/or instability. Partial foot or ankle arthrodesis is particularly advantageous in patients that desire full and uninhibited use of their foot or ankle because more residual motion of the foot or ankle can be preserved.
Currently, in both total and partial foot or ankle arthrodesis scenarios, it is common for plates, implants, wires, screws, staples and external fixation devices to be used as the fusion medium. These devices are used alone or in combination to attempt to achieve the desired level of fusion.
The placement and orientation of the bones of the foot or ankle at the time of a foot or ankle fixation is critical to obtaining a bony fusion, preserving maximal foot or ankle motion in partial fusion, and preventing, for example, progressive arthritis of the foot or ankle. One of the drawbacks encountered with prior art partial fusion devices, methods and instrumentation is that they fail to provide consistent and reproducible fusion, and therefore partial arthrodesis rarely results in full relief of pain. For example, when plates, implants, screws and the like are used to achieve partial foot or ankle fusion, the exact placement of the particular plate, implant or screws from surgeon to surgeon and patient to patient are rarely consistent. As such, the predictability of the exact clinical outcome of partial foot or ankle fusion with such prior art devices is low. As a result, there remains much room for improvement in the art for effective fusion devices, methods and instrumentation that provide reproducible alignment, orientation and configuration of the fusion medium with respect to target fixation bones in order to achieve predictable and consistent fusion of such target fixation bones.
Accordingly, it is an object of the present invention to overcome one or more of the above-described drawbacks and/or disadvantages of the prior art. For example, in view of the deficiencies of current designs of partial foot or ankle fusion devices and methods, and similar fusion devices and methods for other areas of the body where multiple bone structures exist including, but not limited to, the hand, wrist and spine, and the lack of proper associated devices, instrumentation and methods to achieve consistent post-operative results, it would be desirable to develop devices, instrumentation and methods to allow a surgeon to achieve satisfactory long term, predictable clinical outcomes for these types of fusion surgeries.